If you are a git user, you can install the theme and keep up to date by cloning the repo:
$ git clone https://github.com/dracula/mutt.git
Download using the GitHub .zip download option and unzip them.
~/.mutt/ and add the following to your muttrc file:
Receive updates about this theme and more about Dracula.
This theme wouldn't exist without these people. Wanna help too? Check the repository on GitHub.